Safety device for trolley-poles of electric cars.



PATENTED JUNE 20, 1905.

D. R. W. HARDMAN.

SAFETY DEVICE FOR TROLLEY POLES 0F ELECTRIC CARS.

APPLICATION FILED MAR.14, 1905.

3 SHEETS-SHEET 1- III/06722707. Wino/a able.

No. 792,985. PATENTED JUNE 20, 1905. D. R. W. HARDMAN.

SAFETY DEVICE FOR TROLLEY POLES OF ELECTRIC CARS.

APPLICATION FILED MAR.14, 1905.

3 SHEETS-SHEET 2.

No. 792,985. PATENTED JUNE 20,1905. D. R. W.'HARDMAN.

SAFETY DEVICE FOR TROLLEY POLES OP ELECTRIC CARS.

APPLIOATION FILED MAR. 14, 1905.

3 SHEETS-SHEET 3.

UNITED STATES Patented June .O, 1905 PA TENT OFFICE.

SAFETY DEVICE FOR TROLLEY-POLES OF ELECTRIC CARS.

SPECIFICATION forming part of Letters Patent No. 792,985, dated June 20,1905.

Application filed March I l, 1905. erial No. 250,090.

To all whom, it may concern;

Be it known that I, DANIEL RICHARD VVALL- WORK HARDMAN, a subject of theKing of Great Britain, residing in Liverpool, in the county ofLancaster, England, have invented certain new and useful Improvements inSafety Devices for the Trolley-Poles of Electric Cars, of which thefollowing is a specification.

This invention relates to a safety device which is adapted when thetrolley-wheel leaves the overhead trolley-wire to draw down thetrolley-pole clear of the overhead construction, but which shall duringthe ordinary running of the car permit the pole to swivel in either thevertical or horizontal plane and follow the deviations of thetrolley-wire. In such devices the cord attached to the trolleypole isconnected to a conical grooved barrel, which is provided with a springwhich tends to wind up the cord, and so maintains a tension in the cordsufficient to take up the slack, but not sufficient to pull down thepole in opposition to the trolley-pole springs. Coaxial with this barrelis a spring-drum, the spring of which is normally held wound up andwhich if released when the drum is connected to the barrel issufliciently strong to rotate the barrel and pull down the cord. Thedrum and barrel are normally disconnected; but when the trolley-headleaves the trolley-wire electromagnetic means are energized which firstconnect the drum to the barrel and then release the drum.

The drum is provided with what is known as a Geneva stop-motion to limitthe eX- tent to which the drum-spring may be Wound up, and the presentinvention relates to means operated by the locking-piece of the Genevastop and adapted to control both the action of the drum-holding detentand the current which is used to energize the electromagnetic mechanismin such manner that the circuit of the latter is not closed nor thedetent permitted to engage the drum until the drum-spring is fully woundup, the object being to insure that the attendant shall when setting theapparatus fully wind the drum-spring. This construction also secures thefollowing further advantage: As it is impossible for the attendant toset the apparatus with the druml spring only partly wound up and as themovement of the locking-piece which insures this does not close thecircuit of the current to 0perate the electromagnetic means except whenthe drum-spring is fully wound up, the said circuit will be opened assoon'as the drum begins to rotatethat is to say, after the operation ofthe electromagnetic means'so that no more current will be used than isnecessary for the purpose.

The invention also relates to further improvements in regard to the pawlwhich locks the drum to the barrel and to the mode of making theelectrical contact.

The invention is illustrated in the accompanying drawings, in whichFigure I is an elevation, with the casing in section, on the line A A ofFig. II, the trigger-piece 27 and the contact-lever 19 being removed tomore clearly show the remaining parts; Fig. II, a plan, with the barrel,the drum, and the springs in section, on the line B B of Fig. I, thecontact-lever being omitted; and Fig. III, a fragmentary plan to showthe mode of carrying the contact-lever omitted from Fig. II. Fig. IV isa part end elevation showing the mode in which the main detent-lever andthe trigger are operated by the electromagnet. Fig. V is a fragmentarysection of the main detent and trigger lever. Fig. VI is a part endelevation showing the contact-lever and detent-lever in relation to thecam on the locking-piece of the Geneva stop. Fig. VII is an elevationshowing the construction of the pawl and its controllingspring. Fig.VIII is a fragmentary view of the pawl and spring. Fig. IX is asectional elevation of the trolley-pole contact, and Fig. X a sectionalplan of the contact.

Referring in the first instance to Figs. I, II, and III, 1 is the casingin which the apparatus is inclosed, which casing has a suitable cover,which for the sake of clearness is omitted from the drawings. 2 is theconed barrel round which the trolley-rope 3 is adapted to be coiled asthe barrel rotates. 4 is the barrel-spring, one end of which isconnected to the barrel and the other end of which is connected to thefixed shaft 5, on which the barrel and drumrotate. The spring I isjustsufficiently strong to maintain the trolleyrope taut, but not strongenough to pull the trolley-pole down. 6 is the drum, and 7 thedrum-spring, attached at one end to the drum and at the other end to theshaft 5. The drum is rotated till the spring is fully wound up, in whichnormal position the drum is held by the main detent 8. Normally thebarrel is free from the drum. The latter, however, carriesa pawl 9,adapted to engage with the teeth 10 on the barrel. The pawl is normallyheld out of engagement with the teeth by the spring 11 and is providedwith asecond spring 12, which in all positions except the positioninwhich the drum engages with the detent 8 tends to force the said pawlinto engagement with the teeth. WVhen, however, the barrel is fullywound up and in engagement with the detent, a pin 13, fixed to thecasing, engages with the spring 12, as shown in Figs. VII and VIII.

The Geneva stop motion consists of a toothed piece 14, connected to thedrum and rotating therewith, and a lockingpiece 15, carried on a pin ona lever 16. (See Fig. II.) The lever 16 is prevented from rotating by aholding-bracket 17, attached to the casing. When the drum is rotated towind up the drum-spring, the locking-piece prevents further rotationwhen the spring is fully wound up. Attached to the locking-piece andcarried on the same pin as the latter is a campiece 18, having a flat18, which is adapted when the mainspring is fully wound up to come intothe position shown in Fig. VI. The detent 8 and the contact-lever 19bear on this cam-piece, and in all positions of the cam, except thatcorresponding with the fullywound-up position of the drum, the detent 8is held away from engaging with the teeth 20 and the contact-lever isheld away, so that the contact 19 is held clear of the contact 21 of theterminal 21.

The electromagnet 22, which actuates the detent 8, has one end of itswinding connected to 19 and the other end connected to the terminal 23.The two pole-pieces of this magnet, together with its core and winding,are carried by a bracket 24, of non-magnetic substance, and the detentisfulcrumed on a pin- 25, carried from the bracket 24:, the lower end 8 of8 forming an armature of the electromagnet. On the same pin 25 thetriggerlever 26 is carried, its armature 26 being formed of a U-shapedpiece of iron, which passes through clearance-holes in the armature 8The lever 26 bears against a roller on the long arm 27 of the trigger27, the short arm 27 of the trigger bearing against the'tail of the pawl9 when the drum is in normal position. When the electromagnet 22 isenergized, it first attracts the armature 26 of the trigger-lever, whichlatter then so operates the trigger as to cause the pawl 9 to engagecontact 31.

with the teeth 10 on the barrel 2, thus connecting the drum to thebarrel. Immediately afterward the armature 8 is attracted and the maindetent disengaged from the tooth 20, so releasing the drum, whereuponthe strong drum-spring rotates the drum, which, being connected by thepawl 9 to the barrel 2, causes the rotation of the latter and winds downthe trolley-pole.

It will be seen from the construction described that the apparatuscannot be set in normal position until the drum-spring 7 is fully woundup, as otherwise the flat 18 on the cam-piece 18 does not come oppositethe ends of the detent 8 and the contact-lever 19, as shown in Fig. VI,and until the flat 18 comes into this position the detent 8 cannotengage with the tooth 20 nor '19 come into contact with 21", so as tocomplete the circuit through the electromagnet.

In order to prevent the possibility of the spring 11 disengaging thepawl 9- from the tooth 10 during the operation of the apparatus, aspring 12, as described, is provided, which forces the pawl into contactwithithe said teeth. In the normal position of the drum the said pawl ofcourse requires to be free of the teeth, and the spring 12 is thereforerendered inoperative in this position by engagement with a pin 13, asshown in Fig. VIII.

Instead of forming the contact, which closes the circuit of the currentwhich energizes the electromagnet, in the trolley-head itself it ispreferable to pivot the trolley-pole near the trolley-head, as shown inFigs. IX and X, where the upper and lower parts of the pole are pivotedon the axis 28, so that the two parts can pivot relatively toone anotherabout this axis. A spiral spring bears against seatings on the adjacentparts of the upper portion 30 and the lower portion 30- of the pole andnormally tends to bring the axes of these two parts into line, in whichcase the two contact-pieces 31 and 32 engage with each other andcomplete the circuit of the battery and the electromagnet, theconnections being as follows: The terminal 21 is connected to the Theterminal 23 is connectedv to one pole of the battery, and the con-tact32 to the other pole of the battery.

When the trolley is pressed against the trolley-wire, as shown, thetrolley-pole springs cause the two'parts of the pole to pivot about theaxis 28, whereupon the contacts 31 and 32 are separated. When, however,the trolley leaves the wire, the spiral spring brings the two parts ofthe trolley-pole into line, the contacts 31 and 32 engage, the circuitis completed, the pawl 9 engaged with one of the teeth 10 by the actionof the trigger and trigger-lever, after which the detent 8 is drawn fromengagement withthe tooth 20, whereu pon the drum winds the barrel up, asdescribed.

Having now fully describedmy invention,

IIO

1. In combination: a trolley-pole, a light.

spring-controlled barrel connected to the trolley-pole by a rope, aheavy spring-controlled drum, means to connect the drum to the barrel,means to hold the drum wound up, an electromagnetic device to operatethe connecting and holding means, a switch controlling theelectromagnetic means and adapted to close the magnetic circuit when thetrolley-pole is free, a mechanism to limit the winding up of the drum,and means operated by the lockingwheel of the said mechanism whichrender the drum-holding device inoperative except when the drum is fullywound up; substantially as described.

2. In combination: a trolley-pole, a light spring-controlled barrelconnected to the trolley-pole by a rope, a heavy spring-controlled drum,means to connect the drum to the barrel, means to hold the drum woundup, an electromagnetic device to operate the connecting and holdingmeans, a switch controlling the electromagnetic means and adapted toclose the magnetic circuit when the trolley-pole is free, a mechanism tolimit the winding up of the drum, and means operated by the lockingwheelof the said mechanism which rend er the electromagnetic deviceinoperative except when the drum is fully wound up; substantially asdescribed.

3. In combination: a trolley-pole, a light spring-controlled barrelconnected to the trolley-pole by a rope, a heavy spring-controlled drum,means to connect the drum to the barrel, means to hold the drum woundup, an electromagnetic device to operate the connecting and holdingmeans, a switch controlling the electromagnetic means and adapted toclose the magnetic circuit when the trolley-pole is free, a mechanism tolimit the winding up of the drum, and means operated by the lockingwheelof the said mechanism which render the drum-holding device and theelectromagnetic device inoperative except when the drum is fully woundup; substantially as described.

4:. In combination: a trolley-pole, a light spring-controlled barrelconnected to the trolley-pole by a rope, a heavy spring-controlled drum,means to hold the drum wound up, an electromagnetic device to operatethe connecting and holding means, a switch controlling theelectromagnetic means and adapted to close the magnetic circuit when thetrolley-pole is free, a mechanism to limit the winding up of the drum,means to connect the drum to the barrel carried on the drum and normallypressed into operative position by a spring, and a fixed pin which whenthe drum is in its fully-womid-up position renders the last-mentionedspring inoperative; substantially as described.

5. In combination: a trolley-pole, a light spring-controlled barrelconnected to the trolley-pole by a rope, a heavy spring-controlled drum,means to hold the drum wound up, an electromagnetic device to operatethe connecting and holding means, a switch controlling theelectromagnetic means and adapted to close the magnetic circuit when thetrolleypole is free, a mechanism to limit the winding up of the drum,means operated by the locking-wheel of the said mechanism which renderthe electromagnetic device inoperative except when the drum is fullywound up, means to connect the drum to the barrel carried on the drumand normally pressed into operative position by a spring, and a fixedpin which when the drum is in its fully-wound-up position renders thelast-mentioned spring inoperative; substantially as described.

6. In combination: a trolley-pole, a light spring-controlled barrelconnected to the trolley-pole by a rope, a heavy spring-controlled drum,means to hold the drum wound up, an electromagnetic device to operatethe connecting and holding means, a switch controlling theelectromagnetic means and adapted to close the magnetic circuit when thetrolleypole is free; a mechanism to limit the winding up of the drum,means operated by the locking-wheel of the said mechanism which renderthe drum-holding device and the electromagnetic device inoperativeexcept when the drum is fully wound up, means to connect the drum to thebarrel carried on the drum and normally pressed into operative positionby a spring, and a fixed pin which when the drum is in itsfully-wound-up position renders the last-mentioned spring inoperative;substantially as described.

7. In combination with the trolleypole, the barrel, the drum, the Genevastop, the barrelconnecting means, the electromagnetic means, and theswitch which is closed when the trolley-pole is free: the drum-holdingdevice, consisting of a detent-lever adapted to engage with a tooth onthe drum, and a cam on the locking-wheel of the Geneva stop whichprevents the engagement of the said detent until the drum is fully woundup; substantially as described.

8. In combination with the trolley-pole, the barrel, the drum, theGenevastop, the drumholding device, the barrel-connecting device, theelectromagnetic device, and the switch which is closed when thetrolley-pole is free: the lever-controlling contacts in theelectromagnetic circuit and a cam on the Geneva stop which keeps thesaid contact-lever in the off position except when the drum is fullywound up; substantially as described.

9. In combination with the trolley-pole, the barrel, the drum, theGeneva stop, the barrelconnecting device, the electromagnetic device andthe switch which is closed when the trolley-pole is free: thedrum-holding device consisting of a detent-lever adapted to engage witha tooth on the drum, the lever-controlling contacts in theelectromagnetic circuit and a cam on the locking-wheel of the Genevastop which holds the detent-lever from engagement with the tooth on thedrum and holds the contact-lever in its off position eX- cept when thedrum is fully wound up; substantially as described.

10. In combination with means adapted-to pull down a trolley-pole, andan electromagnetic device for releasingsaid means: aswitch, adapted toclose the circuit of said device, and carried at a point of flexure inthe trolley-pole the two contacts of which switch are on opposite sidesof the point of fiexure, and a spring adapted when the trolley-pole isfree 5 hand in the presence of two subscribing Wit- 20 IIGSSBS.

DANIEL RICHARD WALLWORK HARDMAN.

WVitnesses:

J. E. LLOYD BARNES, JOSEPH E. HIRST.

